Pilot harnesses for high speed military aircraft include strap sections which restrain vertical movement of a pilot in a cockpit thereby minimizing the likelihood of injury to the pilot's head and spine as a result of forceful contact with a cockpit canopy. Such a negative "G" strap usually terminates in a lug which engages a lock pin. The latter pin is generally connected to a mechanism, within the seat of the pilot, which withdraws the pin after the pilot has bailed out and prior to separation of the seat from the pilot, in preparation of a parachute landing.
Prior art lug lock mechanisms have exhibited failures during mechanism withdrawal of the lug lock pin due to high radial forces exerted by the weight of the pilot on the lug, the latter being transmitted to the lock pin. As a result, the pin becomes frictionally engaged by the lug thereby preventing it from axially withdrawing from the lug. The result, of course, can be fatal due to late or ineffectual parachute deployment. Accordingly, a need exists for an extremely reliable and secure mechanism for ensuring separation of lug and lock pin when such separation becomes appropriate.